Lw3 vuk coil locked help needed

(Topic ID: 217271)

Lw3 vuk coil locked help needed


By Chochi_ca

4 months ago



Topic Stats

  • 72 posts
  • 5 Pinsiders participating
  • Latest reply 29 days ago by wayout440
  • No one calls this topic a favorite

You

Linked Games

Topic Gallery

There have been 9 images uploaded to this topic. (View topic image gallery).

89B2B415-C565-4DCD-BFFF-AC6DB7710E2C (resized).jpeg
0F27B5EB-A1E9-4F34-A09C-ACD7F1400592 (resized).jpeg
B3CEDFCF-48C9-4996-85DC-AAD4A77AD61C (resized).jpeg
Screenshot_2018-07-22-12-20-08~2 (resized).png
andgate (resized).png
7408 (resized).jpg
CF53101C-F136-4837-9E05-87B6F385142F (resized).jpeg
9440F8D2-E321-4595-B983-C8D3CBA37BAF (resized).jpeg
CFF4313B-28B9-4608-BC54-04A0313317AC (resized).jpeg

There are 72 posts in this topic. You are on page 1 of 2.
#1 4 months ago

So I have been trying to troubleshoot my lw3. My vuk is energized as soon as I power up machine. I have checked the pre drive and drive transistor for the Circuit. Q2 was blown and when I replace it it blows still. I also changed the coil and diode. What else could b causing this?

#2 4 months ago
Quoted from Chochi_ca:

So I have been trying to troubleshoot my lw3. My vuk is energized as soon as I power up machine. I have checked the pre drive and drive transistor for the Circuit. Q2 was blown and when I replace it it blows still. I also changed the coil and diode. What else could b causing this?

there are 4 things that need to be tested/replaced or you will keep doing the same work over and over again.
1.check the coil/-2.diodes(if there are any on that coil)remember a coil rarely ever goes bad unless it is burnt really bad.to test diodes on coil one leg has to be removed.
3.test the main transistor-big one.that drives that coil.
4.test the pre drive transistor-smaller one that drives that coil
the transistor and pre drive transistor will both be located in the manual.location on the driver board as well
the best way is to change out all 4 at the same time.that way it beats blowing out transistors again and double work

#3 4 months ago

There is a pre transistor on the PPB Board also?

#4 4 months ago
Quoted from Chochi_ca:

There is a pre transistor on the PPB Board also?

There is a pre-transistor (2N4401) on the CPU, drive transistor (TIP122 or TIP102 (is better) ) on the CPU and a heavy transistor (TIP36C) on the PPB.
No pre transistor on the PPB, that's the drive transistor on the CPU.

#5 4 months ago

All those transistors test good. Anything else?

#6 4 months ago
Quoted from Chochi_ca:

All those transistors test good. Anything else?

ok,diodes on coil tested good?if there are any

#7 4 months ago

If you are really sure all the transistors (Q16, Q24, on the CPU & Q2 on the PPB)are good, then check the 7408 at 1J.

#8 4 months ago

Ok how would I check 7406? My skills r limited.

#9 4 months ago

Don't get me wroung, but if your skills are limited, how can you be sure the transistors are good?
Do you know what you need to see when using a DMM?

#10 4 months ago

Yes I have been testing with a damn. I have learned how to test transistors. Checking ohm measurements btw legs. I just meant I was limited to the troubleshooting I have done already. Need help with further troubleshooting.

#11 4 months ago

Damn meant dmm. Lol

#12 4 months ago

Double check those coil diodes...
Very important.

I would then disconnect one side of coil wire to prevent blowing out the drive transistor, and put the game in coil test. Then use DMM, oscilloscope, or logic probe to see what is up at CPU CN 12-8. If it is pulsing with coil test, then the problem is downstream. If it is just sitting there, the problem is upstream.

#13 4 months ago
Quoted from Chochi_ca:

So I have been trying to troubleshoot my lw3. My vuk is energized as soon as I power up machine. I have checked the pre drive and drive transistor for the Circuit. Q2 was blown and when I replace it it blows still. I also changed the coil and diode. What else could b causing this?

Is there any way a wire on that coil could be shorting against something metal? I'm trying to think of what could be causing it... Have you checked the diode for Q2? It's D20 on the PPB, right next to Q2. Also check the resistor for it, which is R18, 220ohms. I've seen them burn up too.

Make sure the diode is facing the proper direction on the coil, you can look at other coils for reference for that. Someone may have swapped it out and installed it backwards, stranger things have happened. If you're going to keep the game, it's worth it to keep a few spare TIP 36c's on hand, and the other transistors and pre drive transistors on the cpu board. It has to be something simple, and I hope you figure it out.

#14 4 months ago
Quoted from CanadianGamer:

Is there any way a wire on that coil could be shorting against something metal?

Quick check for that: Unplug J8 PPB and turn on the power.

#15 4 months ago

K I finally had some time to try your ideas out. So I bench tested all transistors, resistors and diodes that we’re mentioned above. I replaced the burned transistors q5 and q3 that I stole to test at q2. I removed the purple yellow wire from the vuk coil. I unplugged cn12 and clipped my red lead on cn12-8 and ground clip on he ground terminal on board. Upon power up I burned q3? Which is for laser kick? Now the problem is even more compicated! Lol. I replaced it again. Transistor was installed with writing up same as others. I only have two more transistors that r new and the one on the board still tests good. I shut off immediately soon as I scene it lighting up. I have to walk away now as frustration has overtaken. I also unplugged the purple yellow wire from the laser kick coil. Still I lights up. Please help

#16 4 months ago

Slow down, take a deep breath. One thing at a time. You replaced a bunch of stuff at once without troubleshooting, so we need to back up a bit.
Remove the vio-yel wire from the laser kick coil for now and ignore that. Focus on the VUK problem.

and ...can you explain this comment:

Quoted from Chochi_ca:

Still I lights up.

When you put your meter on 12-8, set to DCV. Enter diagnostics, coil test mode. Select solenoid #15 (VUK). This pulses the coil circuit, report back if the meter voltage is pulsing or not.

#17 4 months ago

I have already removed the purple and yellow wire from laser kick coil. And it still lights up q3? So I can’t power up the machine.

#18 4 months ago

K my bad I only clipped one of the two purple and yellow wires. I just clipped the other. Machine boots up now with out smoke. Lol. Will test now. 12-8

#19 4 months ago

K here’s a update. With can 12 disconnected I have my red lead clipped on pin 8 and my black lead clipped to ground terminal on board. When I go into test mode and fire vuk coil nothing changed on meter... no voltage. I did notice something. When I was cycling through diagnostics meme. Cycling flashers.. cycled my coils all at the same time but no flashers? When I go into coil test mode. Some of the coil tests r firing two coils at a time? None of my flashers r working

#20 4 months ago
Quoted from Chochi_ca:

Some of the coil tests r firing two coils at a time?

Sounds like you have upper level logic issues, something wrong further upstream than output circuit/driving transistors. Could be a bad PIA or something else that would be causing that. Perhaps ICs were damaged by coil backlash from a bad diode. Lots of possibilities.

Just because the questions were not asked earlier:
Did the game ever work in your possession? (meaning: Did these problems just suddenly crop up?....or has the game never worked since you got it?)
Was there some kind of work you or someone else did leading up to and just prior to the game failing?
Any signs of corrosion damage or battery leakage?
Board rework?
Can you post pictures?

Another possible venue to explore is to document which coils are coming on simultaneously - provided they are consistent and not random. Then we might be able to zero in on a particular PIA, IC or some other common factor.

#21 4 months ago

Yes I should have disclosed this to begin with. I bought the machine in rough shape. There was also battery leakage from the batteries. The machine would not boot. I removed the batteries and cleaned the holster. Installed new and machine booted and played functional. I was missing the mars light and the knocker coil. So I ordered shop out parts. Replaced rubbers, lights, burnt connectors on the gi, ordered a beacon from amazon and replaced knocker coil. Upon boot up the mars beacon continuously lit. So I reclaced the drive transistor. But the traces for the transistor on the board where damaged so I ya to hack a couple of traces. I had to jump the ground leg to the drive transistor leg next to it. Not the vuk transistor the other(got no print right now). I didn’t think this would b a issue because all the transistors shared that ground leg? That’s when I booted the machine and smoked the vuk coil. I tested for continuity btw transistors and none was present. All transistors tested the same. I will record which coils r firing together tmrw when I can get back to it.

#22 4 months ago

K here’s a update on the coils firing.
In cycling flashers mode trough, both drop targets and all outholes continuously cycle at the same time... no flashers. During cycling coils mode
#1l fires outhole
#1r fires outhole
#2l nothing
2r nothing
3l nothing
3r nothing
4l left outhole
4R left outhole
5l right outhole
5r right outhole
6l center drop target
6r center drop target
7l right drop target
7r right drop target
8l knocker nothing(coil disconnected)
8r nothing
9 nothing
11 gi flashes
12 nothing
13 nothing
14 nothing(disconnected)
15 nothing(coil disconnected)
16 nothing
17 left bumper
18 center bumper
19 right bumper
20 left along
21 right sling
22 nothing (coil disconnected)

None of my flashers work during test

CFF4313B-28B9-4608-BC54-04A0313317AC (resized).jpeg

9440F8D2-E321-4595-B983-C8D3CBA37BAF (resized).jpeg

CF53101C-F136-4837-9E05-87B6F385142F (resized).jpeg

#23 4 months ago

wow,i cant believe this thread went from locked on coil to all this

#24 4 months ago

Bump

#25 3 months ago

It looks like your left/right relay is not switching.

First Test the Solenoid L/R Select Relay!
When the solenoid A/C select relay is not working correctly, there can be all kinds of coil problems. A malfunctioning L/R relay, if stuck on or off, won't give any power to either the coils or flashlamps. If the relay is constantly energized (stuck on bank "R"), it's probably because it's driver transistor Q29 is shorted on.

On most DataEast/Sega games, the "L" (or "A") bank was for coils, and the "R" (or "B") bank is for flashlamps. But on games from Time Machine to the Simpsons, this logic was reversed. In these games the "L" bank was used for flashlamps (instead of coils), and the "R" bank was used for coils (instead of flashlamps). Keep this in mind when diagnosing problems.

The first thing to do is to test the solenoid L/R select relay. Turn the game on, and enter diagnostics (entering diagnostics should de-energize the L/R relay; on some games the L/R relay will stay energized after finishing a game because of an after-game flasher light show). Take an alligator test wire and connect it to the metal tab on transistor Q29. Then with the game on and in attract or diagnostic mode, touch the other end of the alligator clip to the ground strap in the backbox (WWF Royal Rumble and later, make sure the coin door is closed). The L/R select relay on the PPB board should click "on and off"; it will click on when the transistor is grounded, and off when not.

#26 3 months ago

Ok have tested the method above. With my alligator on the metal tab of q29 and the other end grounded the relay is opening and closing only some of the times that I ground it. I tested q29 and the pre transistor and both test good. Is the relay sticking? Or is it the signal that is not telling it to open/close?

#27 3 months ago
Quoted from Chochi_ca:

Ok have tested the method above. With my alligator on the metal tab of q29 and the other end grounded the relay is opening and closing only some of the times that I ground it. I tested q29 and the pre transistor and both test good. Is the relay sticking? Or is it the signal that is not telling it to open/close?

it should open/close every time you ground it.

All DataEast/Sega games have a minimum of three relays in the backbox. These relays are a source of common problems on these games. Most common is cold solder joints where the relay is soldered to the circuit board. The relays themselves can also fail however. These relays really aren't repairable; just replace them. Often the contacts on the relay switches will burn together so the relay cannot do its job.

PPB/MRB board relay K1: this relay controls the solenoid L/R select circuit, and is controlled by CPU transistor Q29 (TIP122). It is extremely common for this relay to have cold solder joints! If the L/R (or A/B) select coils or flashlamps do not work, this relay should be checked. This relay is a 24 vdc 10 amp relay with two DPDT switches. There are a total of 8 solder points on this relay; two connect to the winding of the relay coil (to turn the relay on and off). The other six contacts (two distinct sets of three contact DPDT switches) are the relay switches. Source number FRL264 P024/02CK, Sega part 190-5002-00.

http://techniek.flipperwinkel.nl/desega/index1.htm

#28 3 months ago

Ok so I resoldered all the pins for the relay on the ppb board. Now when i test with alligator clips the relay does open(clicks) everytime I ground q29. So I tried to connect my laser kick coil. Powered up and it’s burning away at q3 still(transistor was bad before I tested already) does that matter? Only have a couple transistors left. So I diconnected the coil again. I tried to connect my vuk coil again to. Upon power up it still locks up. I noticed All the metal tabs for the 5 transistors q1-q5 on the ppb board short to ground. Is this normal? Games is cycling flashers properly now

#29 3 months ago

I also noticed when I unplug cn12-8 the flashers stop working during “flasher test” it only runs actuating coils.

#30 3 months ago
Quoted from Chochi_ca:

I noticed All the metal tabs for the 5 transistors q1-q5 on the ppb board short to ground. Is this normal?

Yes, pin 2 (collector) has electrical continuity to the mounting tab on a TIP36C

#31 3 months ago
Quoted from Chochi_ca:

I also noticed when I unplug cn12-8 the flashers stop working during “flasher test” it only runs actuating coils.

Probably some other stuff stops working as well.

Quoted from Chochi_ca:

Powered up and it’s burning away at q3 still(transistor was bad before I tested already) does that matter? Only have a couple transistors left. So I diconnected the coil again. I tried to connect my vuk coil again to. Upon power up it still locks up.

Eeek. You really shouldn't repeatedly power up a game with shorted transistors, and if you know a driver transistor is shorted don't connect it back up - you risk damaging the coil since it was designed to be on momentarily. Best to removed the damaged components first, so you don't cause additional damage. Troubleshoot and find out what else is wrong upstream first. A coil drive transistor is just wired as a "dumb switch" in pinball - it has to be "told" what to do by an electrical state change on its input.

#32 3 months ago

How would I go about testing the 7406 at 1J?

#33 3 months ago

Are you sure that is a 7406? I think it is a 7408 quad AND gate

#34 3 months ago

No not sure at all. I was just referencing a previous post in the thread.

#35 3 months ago
Quoted from wayout440:

Are you sure that is a 7406? I think it is a 7408 quad AND gate

It's very hard to read in the schematics.
It is definately a 7408 chip at position 1J.

Sometimes when a gate is shorted to ground, you can check it with a DMM.
Put one lead on the ground connection and the other lead to pin 3, 6, 8 & 11 (gate 1, 2, 3, 4).
If one is shorted to ground you will see 0.00V.

#36 3 months ago

I checked all 4 of the 7408 chips above the drive transistors. All the test points read around .160v dc

#37 3 months ago
Quoted from Chochi_ca:

I checked all 4 of the 7408 chips above the drive transistors. All the test points read around .160v dc

To check the gates, you should be in coil test mode. Each gate has two inputs. There are four gates on each 7408 IC. One input to each gate is a coil trigger signal, and the other is blanking. Blanking must be logic high, then when a high trigger pulse occurs on the other gate input, the output of that gate pulses high.

If you measure .160 VDC. (Logic low) on the blanking inputs in coil test, the coils would not work.

7408 (resized).jpg

#38 3 months ago

Appreciate the description. I found the correct legs for the vuk. One leg has a 5vdc supply. The other two when coil is pulsed through coil test maxes out at .8vdc. I found the correct legs for a working coil and it was reading almost 5vdc when pulsed. Does that mean my 7408 needs to b replaced? That would cause my coil to b locked on? Thought it just wouldn’t cycle?

#39 3 months ago
Quoted from Chochi_ca:

Appreciate the description. I found the correct legs for the vuk. One leg has a 5vdc supply. The other two when coil is pulsed through coil test maxes out at .8vdc. I found the correct legs for a working coil and it was reading almost 5vdc when pulsed. Does that mean my 7408 needs to b replaced? That would cause my coil to b locked on? Thought it just wouldn’t cycle?

Hmmm. Might be more than one problem. Q29 has a predriver Q21, that could be bad and locked on, or something else in the vincinity, so you might want to look at that. It might be that Q21 has failed and is holding the gate output low at its input - but keeping a high on the base to Q29 resulting in the locked on condition. Some will advise that a predriver transistor should be replaced when a driver transistor is replaced.
The gate that is not functioning: are you saying that A (which we will call the blanking signal) is 5VDC and on B when it pulses to 5VDC, you do not get a pulsed high output at AB? If so, then the gate is probably failed and needs replaced.

andgate (resized).png
#40 3 months ago

K before I check that I just ran my coil test and i have multiple problems. Here r the results of my test.

Coil test
1l outhole...nothing
1r flash.... working
2l trough eject.... nothing
2r 3 panel flash.... nothing.
3l not used..... nothing
3r flash... working
4l left saucer... working
4r flash.... working
5l right saucer..... working
5r flash... working
6l center drop target.... working
6r flash... working
7l right drop target... working
7r flash.... working
8l knocker.... disconnected
8r flash... working
9 flash... working
11 gi.... working
12 ball launch... working
13 coil not used
14 mars..... disconnected
15 vuk..... disconnected (coil locks on when connected)
16 flash.... nothing
17 left bumper... working
18 center bumper... working
19 right bumper... working
20 left sling... working
21 right sling.... working
22 laser kick... disconnected(when connected burns q3 on ppb board)

I can hear the r/l clicking but maybe it’s not working? Maybe it is related to those transistors u have mentioned ? But I have removed the board and tested as per pinwiki repair guide and they test ok. And wouldn’t only c the same coils not firing if those transistors whet a issue? Plus I have the problems with coils 16, and 22. Is there a component that shares all these collectively?

#41 3 months ago

The PIAs will do the bulk of the controlling, bit that is not where I would start. If you roll through the coil tests more than once, verify that the same set of coils work or don't work repeatedly. If they change imtermittently, that's more difficult to resolve.
Your LR relay appears to be functioning properly from the results you posted.
I would pick one problem at a time to solve,
Knowing the transistors themselves are ok is fine, but that's a fraction of what happens to make the coils work. One method is to pick a working coil circuit to compare measurements of those signals with the failed circuit.

#42 3 months ago

It’s def the same coils cycled it a few times over. Started off with just vuk. Then it was laserkick. Then trough eject... outhole... flashers. it seems everytime time I remove the boards and reinstall I lose more coils.

#43 3 months ago
Quoted from Chochi_ca:

It’s def the same coils cycled it a few times over.

OK, consistent is a little bit easier to deal with...but still requires a lot of patience.

Quoted from Chochi_ca:

1l outhole...nothing
1r flash.... working

Starting at the top pf your list, what does this tell you? These L/R relay multiplexes the outhole coil with this flasher to utilize the same transistor.
so:
The outhole drive transistor and its upstream circuit are good.
The L/R relay works

Now I would start with basic coil non functional checks. Is the outhole coil getting solenoid DC power to it? The L/R relay is normally closed until it is energized to operate the R side flasher, so in coil test you should be able to see DC voltage sitting on the outhole coil tabs. If it is there, you should be able to briefly short the coil tab to make sure the coil fires and the coil itself is good. Then check at CPU by grounding tab briefly on Q46 solenoid driver. If the coil doesn't fire, you have a continuity problem to track down and usually that is a bad connector Sometimes you'll find a problem like this will also help to identify others.

#44 3 months ago

Ok thanx again wayout440. Ur knowledge patience is greatly appreciated. Will get back to the machine later today.

#45 3 months ago
Quoted from wayout440:

in coil test you should be able to see DC voltage sitting on the outhole coil tabs. If it is there, you should be able to briefly short the coil tab to make sure the coil fires and the coil itself is good.

meant to say short trigger side tab

#46 3 months ago

Ok so I got back to the machine. I fixed some of the coils that were not working(cracked solder joints on ppb board). Back to troubleshooting the vuk locked on. When pulsing the 7408 chip for vuk I’m not gettin enough voltage on the two legs. It stays under 1v. I tested another working coil and when pulsed the other legs read highs of almost 5dc and the other round 3vdc. Does this mean my 7408 chip is bad and needs replacement? Causing my coil to be locked on??

#47 3 months ago

I have also noticed that my coil voltages are reading higher then stated. My coil that are listed at 32vdc are running at 45vdc and my 50vdc coils are running at 84 vdc. Is this also a problem? The coils that are working are working with those voltages.

#48 3 months ago

It could be the 7408, but also check the pull up resistor pack on the output. I think its RA7. That is another possibility. Its not uncommon for those to fail.

The coil voltages appear ok. It is not unusual for the variance you are seeing.

1 week later
#49 3 months ago

Back at it. I tested my 7408 again and it’s def not supplying enough voltage for the vuk. Under 1v are I’m reading for the logic high/low legs. U also told me to test the ra7 pull up resistor? It think it’s r9 and I isn’t downstream from my voltage problem ?

1 week later
#50 3 months ago

I checked ra9. Tests good. I’m gonna order a 7408 chip if no one else has other ideas?

Promoted items from the Pinside Marketplace
$ 30.00
Electronics
Yorktown Parts and Equip
From: $ 99.99
Cabinet - Other
Lighted Pinball Mods
$ 40.00
Lighting - Other
Rock Custom Pinball
From: $ 369.95
Boards
PinSound
From: $ 40.00
Lighting - Interactive
Professor Pinball
3,400 (OBO)
Machine - For Sale
Luling, LA
$ 15.00
Playfield - Decals
Metal-Mods
From: $ 16.95
1,400 (OBO)
Sale Pending!
Albany, NY
€ 95.00
Lighting - Led
FlipperLED
$ 9.99
Eproms
Matt's Basement Arcade
$ 149.00
$ 15.00
Playfield - Protection
Professor Pinball
There are 72 posts in this topic. You are on page 1 of 2.

Hey there! Got a moment?

Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside